How to validate empty space in textbox in Javascript

• Validate variable if value of variable is null, empty and has blank spaces in javascript

  <script>
  function isNullEmptyBlank(str){
      return str === null || str.match(/^ *$/) !== null;
  }
  
  var addr = '';
  
  if(isNullEmptyBlank(addr)){
    console.log('The value of variable is null, empty or has blank spaces');
  }
  </script>
  

  Output:

  The value of variable is null, empty or has blank spaces

  This code snippet will validate input variable if value of variable is null (null), empty ('') and has blank spaces(' ').

   

   

• Validation for empty spaces in javascript using regex

  <script>
  function hasBlankSpaces(str){
      return  str.match(/^\s+$/) !== null;
  }
  var addr = ' ';
  if(hasBlankSpaces(addr)){
    console.log('The variable has blank spaces');
  }
  </script>
  

  Output:

  The variable has blank spaces

  This code snippet will help you to find out the variable has blank spaces or not.

• How check field is empty or not in JavaScript?

  Use the condition with “” and NULL to check if value is empty. Throw a message whenever ua ser does not fill the text box value.

• How check TextField is empty?

  Since we created an instance of the TextField class named text, we take text and get its value and use the isEmpty() function to see whether it is empty or not. And this is all that is required to check whether a text field is empty or not in a JavaFX application.

• How do you check if a value is empty?

  The empty() function checks whether a variable is empty or not. This function returns false if the variable exists and is not empty, otherwise it returns true. The following values evaluates to empty: 0.

• How do you know if a field is null?

  SELECT * FROM yourTableName WHERE yourSpecificColumnName IS NULL OR yourSpecificColumnName = ' '; The IS NULL constraint can be used whenever the column is empty and the symbol ( ' ') is used when there is empty value.

• Does isEmpty () check for null?

  isEmpty(< string >)

  Checks if the value is an empty string containing no characters or whitespace. Returns true if the string is null or empty.

• What is the difference between null and blank?

  Answer: Null indicates there is no value within a database field for a given record. It does not mean zero because zero is a value. Blank indicates there is a value within a database but the field is blank.

• How do you restrict the input field space?

  Step 1: Create React Project. Step 2: Create Component File. Step 3: No Space Validation. Step 4: Update App Js File. Step 5: Start React App.

• What is form validation JavaScript?

  JavaScript provides a way to validate form's data on the client's computer before sending it to the web server. Form validation generally performs two functions. Basic Validation − First of all, the form must be checked to make sure all the mandatory fields are filled in.

• How do you validate a textbox in HTML?

  To validate the form using HTML, we will use HTML <input> required attribute. The <input> required attribute is a Boolean attribute that is used to specify the input element must be filled out before submitting the Form.

• How do I prevent TextBox space?

  You can restrict the user to enter space in the textbox control by disabling keycode for space key. You can acieve this by using Ajax toolkits (FilteredTextBoxExtender). Hi, you can USE VALIDATE WITH REGULAR EXPRESSION AND javascript.

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